@* Consistent placeholder for async-loaded pages/dialogs. Replaces the
   ad-hoc `<p>Lädt…</p>` sprinkled across pages after PR P made every
   OnInitializedAsync truly async. Kept as a pure visual — callers keep
   their existing null-guard and just render this while data is loading. *@

<div style="display: flex; flex-direction: column; align-items: center; gap: 0.5rem; padding: 2rem;">
    <FluentProgressRing/>
    <FluentLabel>Lädt…</FluentLabel>
</div>